1. Field of the Invention
The present invention relates to a built-in antenna assembly installed in a wireless telecommunication terminal, more particularly which more stably ensures electrical contact between the built-in antenna and a substrate, and enhances assembling capabilities due to simper configuration.
2. Description of the Related Art
In general, a wireless communication terminal refers to a portable communication device capable of transmitting/receiving voices, texts and image data through wireless communication. The examples include a personal communication service (PCS) terminal, a Personal Digital Assistant (PDA), a smart phone, a next-generation mobile communication (IMT-2000) terminal, a wireless LAN terminal and the like.
The wireless communication terminal adopts a helical antenna or a dipole antenna to enhance its transmission and reception sensitivity. These are external antennas, which thus are extended out of the wireless terminal.
The external antennas are advantageously characterized by non-directional radiation. At the same time, they are disadvantageously prone to damage by external force, hardly portable and designed with poor aesthetic appearance.
To overcome such a problem, plate-shaped built-in antennas such as a micro-strip patch antenna or inverted F-type antenna have been recently adopted in the wireless communication terminal since they can be installed in the terminal without being extended outward.
FIG. 1 is a perspective view illustrating a conventional built-in antenna assembly. The built-in antenna assembly 10 includes abase 11, a radiator 12 and a terminal 13 and is mounted on a substrate (not illustrated).
The base 11 is a structure fixed onto the substrate 11. The radiator 12 is made of dielectrics and disposed on an upper surface of the base 11, constituting a transmitter/receiver of the antenna. The terminal 13 is made of the same dielectrics as the radiator. The terminal 13 includes a feeding pin 13a and a ground pin 13b grounded to a feeding part formed on the substrate.
FIGS. 2(a) and (b) and FIGS. 3(a) and (b) illustrate various terminal supporting structures 20 and 30. The terminal supporting structures 20 and 30, when mounted on the substrate, prevent defective electrical contact between the terminal 13 and the substrate, ensuring stable contact therebetween.
The conventional terminal supporting structure 20 shown in FIGS. 2(a) and (b) is a forward terminal supporting structure. That is, a guider 21 has a guide hole 21a so that the terminal bent inwardly (rightward in FIG. 2) in a longitudinal middle part is inserted in the guide hole 21a. Also, a rubber member 23 is disposed underneath the base 11 corresponding to an upwardly bent bending part 14 which is formed on a lower end of the terminal 13. Here, the terminal 13 inserted into the guider 21 formed on a leading end of the base 11 is positioned in an inward direction of the base.
In this case, when the base 11 of the built-in antenna 10 and the substrate P are assembled together, the terminal 13 supported by the terminal supporting structure 20 is inclined downward at a predetermined angle 01 from a horizontal line when the bending part 14 is in contact with a contact pad 25 disposed on the substrate P. Here, the terminal 13 is elastically deformed to absorb pressure from A direction and elastically spring back.
In addition, the conventional terminal supporting structure 30 of FIGS. 3(a) and (b) is an inverse terminal supporting structure. That is, a guider 31 has a guide hole 31a so that a terminal 13 bent outward (leftward in FIG.3) in a longitudinal middle part is inserted into the guide hole 31a. A rubber member 33 is disposed underneath the guider 31 corresponding to a bending part 14 which is bent upward on a lower end of the terminal 13. The terminal 13 inserted into the guider 31 formed on a leading end of the base 11 is positioned in an outward direction from the base 11.
In this case, when the base 11 of the built-in antenna 10 and the substrate P are assembled together, the terminal 13 is inclined downward at a predetermined angle θ2 from a horizontal line when the bending part 14 is in contact with a contact pad 35 formed on the substrate P. Here, the terminal 13 is elastically deformed to absorb pressure from A direction and elastically spring back.
However, in the built-in antenna 10 employing this conventional terminal support structure 20 and 30, the terminal 13 should be bent in an adequate extent to be electrically connected to the contact pad 25 and 35 when the built-in antenna 10 and the substrate P are assembled together. That is, a working distance between the bending part 14 of the bent terminal 13 and the contact pad 25 and 35 and weight gathered on the terminal 13 should be taken into account. But it is time-consuming to design the terminal in this fashion, and any errors in design may cause defective contact between the bending part 14 and the contact pad 25 and 35, failing to produce a circuit.
Also, in assembling the built-in antenna 10, it is an intricate job to manually draw downward the terminal 13 extended from the radiator 12 through the guide hole 21a and 31a of the guider 21 and 31. Thus this undermines work productivity.
Moreover, the terminal set providers do not have any design standard for the terminal which universally covers various terminal types. Therefore it is difficult to perform RF matching and form the terminal 13 or the contact pad 25 and 35 uniformly in a desired position of the antenna. On the contrary, the terminal 13 needs to be individually tailor-designed for respective various terminal models.